Roller trains, particularly to distribute ink in the inking system of a printing machine, frequently use a plurality of rollers which are so arranged that some rollers hide other rollers therebeneath, so that access to the inner ones of the rollers is impaired. In some structures, it is desirable to permit movement of rollers towards or away from another engaged roller. British Pat. No. 1,422,421 describes an inking system in which a plate cylinder is inked by a plurality of ink application rollers. The ink application rollers, in turn, receive ink over two roller trains. To permit change-over, or to engage and disengage the inking system, one further roller can be pivoted or tipped about a roller which is journaled in fixed bearings, maintained in a predetermined position in the frame. Such roller trains have disadvantages in that it is difficult to replace certain rollers without disassembling the entire roller train, and particularly without disassembling the rollers which hide the inner ones, or the ones covered thereby. Thus, maintenance and/or exchange of some of the rollers beneath outer ones is difficult, time-consuming, and expensive.